Sermons delivered by Catholic priests are often painfully "grey and dull" and need to be livened up with the "scandal" contained within the Bible, the Vatican's most senior cultural official said.

Cardinal Gianfranco Ravasi said preaching in churches had become so formulaic and boring that it risked becoming "irrelevant" to congregations accustomed to the excitement and immediacy of television and the internet.

"The advent of televised and computerised information requires us to be compelling and trenchant, to cut to the heart of the matter, resort to narratives and colour," said the cardinal, who as the head of the Pontifical Council for Culture is the Vatican's unofficial minister for culture.

Too many priests employed theological language that was "grey, dull and flavourless" and instead should spice up their sermons with graphic stories contained in the Bible, which used much more forceful imagery.

The Bible was "crowded with stories, symbols and images," he said.

Speaking at a conference in Rome, he said Twitter was also an effective way of spread the Word of God.

"We need to remember that communicating faith doesn't just take place through sermons. It can be achieved through the 140 characters of a Twitter message."

Cardinal Ravasi, a champion of new media who writes a blog for the website of Italy's respected financial daily, Il Sole 24 Ore, said that whether they liked it or not, priests in the pulpit should be aware that their congregations were "the children of television and the internet."